1. Field of the Invention
This invention belongs the field of the data transfer system that deals with the information of living organisms such as a human, a horse, a cow a, a dog, etc.
2. Description of the Prior Art
There exist a variety of communication methods that transfer the data of living organism through a mobile radio link. The most are the method that a mobile station actively emits the data and the immobile station receives the data transmitted by the mobile station. In other words the data emission is with very high power and reception of data is forced by high power emission, or existence of radio echo repeater between the emitter and the receptor helps the reception by means of data communication by passing the radio echo repeater, or existence of multiple receptors increases a chance of data reception. Frequently a mobile radio station is operated by a battery so that frequent change or recharging of the battery is forcefully required if the high power data emission is performed.
In order for a human to carry radio equipment, the weight and the size of the radio equipment must be limited. A radio transceiver usually needs to be integrated in an item such that the person who carries the radio equipment does not feel uncomfortable. For example, in the case of radio equipment integrated in a wrist watch, the person may always carry the wrist watch because most wrist watches are waterproof and there is no need to remove the wrist watch while bathing or work related to water. However, for carrying the wrist watch on a user's hand, the battery has to be small and frequent change or recharging of battery is necessary if frequent radio communication is performed. The battery life of the radio equipment integrated in a wrist watch is determined by the transmission power, the frequency of the communication and transmission duration. For the application field of status monitoring, such as monitoring the status of elderly people, it is a complicated task for an elderly person to change or recharge the battery frequently. On the other hand, decreasing transmission power in order to minimize power consumption makes it difficult for the receptor to receive the data.
Moreover, in the case that the radio equipment is attached to the wrist, the polarization of radio wave waves emitted from the radio equipment on the wrist changes time to time when the user's hands are moved during the transmission and reception because movement of the human hand is complicated. For the reception of a direct wave, a change in polarization plane results in a change in induced current on an antenna. In other words, readability varies as a function of time. For this reason, the radio wave emitted from the mobile station may not always reach the immobile station with effective strength. This phenomenon causes a problem in that the radio equipment of the immobile or base station may not receive a signal even if a health status change occurred in the person who carries the mobile station.